Motor and method of producing motor

Abstract

In the present invention, a stator 3, which constitutes a motor along with a rotor, comprises: an annular stator core comprising a plurality of teeth 42; an insulator; and a plurality of windings 6. The ratio of the number of poles of the rotor to the number of slots of the stator core is 2:3. Each of the windings comprises: a plurality of coil sections 61 wound around the teeth; two lead wires 63 that constitute ends of the winding and extend from the coil sections; and jumper wires 62 the mutually different phases of which are accommodated in a plurality of crossover slots 52 of the insulator and which connect adjacent coil sections. A lead wire is drawn out from one side of the coil section in the circumferential direction, a jumper wire is drawn out from the other side in the circumferential direction of the coil section, and a jumper wire drawn out from the other side in the circumferential direction of the coil section extends to the other side in the circumferential direction with respect to the coil section.

Description

Motor and motor manufacturing method

[0001] This application claims priority to Japanese Patent Application No. 2024-029670, filed February 29, 2024, the contents of which are incorporated herein by reference.

[0002] Patent Document 1 discloses a stator (armature) for a motor (electric motor) that includes a stator core, windings, and an insulator. The stator core has multiple slots and multiple teeth formed between the slots. The windings are made of a single wire (solid wire) or a multi-strand wire formed by bundling multiple wires in a non-aligned manner. The windings include multiple coil portions wound around each of the multiple teeth, connecting portions (crossover portions) that connect the coils, and two lead portions extending from both coil portions to form the ends of the windings. The crossover portions are housed in crossover grooves that extend circumferentially on the outer periphery of the insulator. A three-phase AC motor has windings for three phases. The crossover portions of the windings for the three phases (U phase, V phase, and W phase) are housed in three crossover grooves aligned axially of the insulator to electrically insulate the windings of different phases from each other. In order to achieve electrical insulation between windings of different phases, it is necessary to ensure a sufficient creepage distance between the crossover wire portions housed in different crossover grooves.

[0003] International Publication No. 2012 / 133302

[0004] Depending on the manner in which the windings are attached to the stator core and insulators, the crossover wires and lead wires constituting the same winding may cross each other. Furthermore, the crossover wires constituting the same winding may cross each other in the crossover grooves. However, if a specific crossover wire crosses a lead wire or another crossover wire in the same winding, the specific crossover wire may overflow the crossover groove or enter a crossover groove containing a crossover wire of another phase, causing the winding to collapse.

[0005] The present disclosure has been made in consideration of such problems, and aims to provide a motor and a method for manufacturing the motor that can prevent the winding from becoming unwound.

[0006] A motor according to one aspect of the present disclosure includes a rotor, a stator including an annular stator core having a plurality of teeth and a plurality of slots arranged in a circumferential direction, an insulator attached to the stator core, and a plurality of windings wound around the plurality of teeth via the insulator, wherein when the number of poles of the rotor is P, the number of slots of the stator core is S, and n is a natural number equal to or greater than 2, P:S=2n:3n or P:S=4n:3n the insulator has a winding holding portion disposed on either one end side in the axial direction of the stator core, the winding holding portion being recessed from the outer periphery, extending in the circumferential direction, and having a plurality of jumper grooves aligned in the axial direction, the plurality of windings each having a plurality of coil portions wound around the teeth by concentrated winding, pull-out wire portions that form ends of the windings and extend from the coil portions, and jumper wire portions of different phases housed in the plurality of jumper grooves and connecting adjacent coil portions, the coil portions from which the pull-out wire portions are pulled out from one side in the circumferential direction have the jumper wire portions pulled out from the other side in the circumferential direction, and the jumper wire portions pulled out from the other side of the coil portions in the circumferential direction extend to the other side in the circumferential direction relative to the coil portions.

[0007] A method for manufacturing the motor, wherein each of the plurality of windings is formed by carrying out the following steps: a first step of forming a first coil portion by concentrating winding from one circumferential side of a first tooth around the first tooth while forming a first pull-out portion; a second step of forming a jumper portion after the first step by pulling out to the other circumferential side of the first tooth and extending to the other circumferential side of the first tooth while being accommodated in the jumper groove; a third step of forming a second coil portion after the second step by concentrating winding from one circumferential side of a second tooth located away from the first tooth on the other circumferential side; and a fourth step of forming a second pull-out portion after the third step by pulling out to the other circumferential side of the second tooth.

[0008] According to the present disclosure, it is possible to prevent the windings in a motor from becoming unwound.

[0009] 1 is a cross-sectional view schematically illustrating a motor according to an embodiment of the present disclosure; FIG. 2 is a perspective view illustrating an example of a stator in the motor of FIG. 1 when the number of slots is 36; FIG. 3 is a cross-sectional view of an example of a motor in the motor of FIG. 1 when the number of poles of the rotor is 4 and the number of slots of the stator is 6, as viewed from the axial direction; FIG. 4 is a circuit diagram illustrating an example of a three-phase AC circuit in the stator according to an embodiment of the present disclosure when the number of slots is 6; FIG. 5 is a diagram illustrating an example of a winding connection diagram, divided into U-phase, V-phase, and W-phase, in the stator according to an embodiment of the present disclosure when the number of slots is 6; and FIG. 6 is a diagram illustrating another example of a winding connection diagram.

[0010] An embodiment of the present disclosure will be described in detail below with reference to Figures 1 to 5. In this embodiment, the direction parallel to the axis O of the rotor 2 and the stator 3 in Figures 1 to 3 is referred to as the axial direction. The radial direction is the direction that radiates from the axis O. The circumferential direction is referred to as the circumferential direction. Furthermore, in this embodiment, one side in the axial direction is referred to as the upper side or upward direction, and the other side in the axial direction is referred to as the lower side or downward direction. In the radial direction, the direction approaching the axis O is referred to as the radially inner side, and the direction away from the axis O is referred to as the radially outer side.

[0011] <Motor> As shown in FIGS. 1 and 3 , the motor 1 is a three-phase AC motor and includes a rotor 2 and a stator 3. The rotor 2 includes a rotor shaft 21, a rotor core 22, and a plurality of magnets 23. The rotor shaft 21 is a rod-shaped member centered on an axis O. When viewed from the axial direction, the rotor shaft 21 is formed in a circular shape centered on the axis O and is rotatable about the axis O. The rotor core 22 is formed in a cylindrical shape centered on the axis O. The rotor core 22 is fixed to the outer circumferential surface of the rotor shaft 21. The rotor core 22 may be formed, for example, from a plurality of steel plates stacked in the axial direction. The magnets 23 are permanent magnets. For example, when each of the plurality of magnets 23 forms one magnetic pole, the plurality of magnets 23 may be arranged at equal intervals in the circumferential direction of the rotor 2 on the outer periphery of the rotor 2. Furthermore, for example, one magnetic pole may be formed by the plurality of magnets 23. The multiple magnets 23 constituting one magnetic pole may be arranged at equal intervals in the circumferential direction of the rotor 2 on the outer periphery of the rotor 2. The magnets 23 may be embedded inside the rotor core 22 as shown in Figures 1 and 3, or may be attached to the surface of the rotor core 22, for example.

[0012] <Stator> As shown in Figures 1 and 2, the stator 3 includes a stator core 4, an insulator 5, and a plurality of windings 6. <Stator Core> The stator core 4 is formed in a cylindrical shape centered on the axis O. The rotor 2 described above is rotatably housed inside the stator core 4. The stator core 4 includes a cylindrical yoke 41, a plurality of teeth 42, and a plurality of slots 43.

[0013] The multiple teeth 42 protrude radially inward from the inner peripheral surface of the yoke 41 and are arranged at intervals in the circumferential direction of the stator core 4. Slots 43 are formed between circumferentially adjacent teeth 42. As a result, the multiple teeth 42 and the multiple slots 43 are formed alternately in the circumferential direction of the stator core 4. Specifically, the multiple teeth 42 are formed to have the same shape and size, and are arranged at equal intervals in the circumferential direction. Therefore, the multiple slots 43 are arranged at equal intervals in the circumferential direction of the stator core 4. As a result, the multiple teeth 42 and the slots 43 are formed alternately in the circumferential direction at equal intervals.

[0014] The stator core 4 is formed by, for example, laminating a plurality of electromagnetic steel sheets in the axial direction. The stator core 4 may also be formed by, for example, powder molding.

[0015] <Insulator> The insulator 5 is attached to the stator core 4 so as to cover at least a portion of the surface of the stator core 4, with the aim of electrically insulating the winding 6, which will be described later, from the stator core 4. In Figures 1 and 2, the insulator 5 covers at least the outer peripheral surface of each tooth 42 around which a coil portion 61 of the winding 6, which will be described later, is wound, and the inner peripheral surface of the yoke 41 on which the teeth 42 are installed. The insulator 5 is an insulating member. The insulating member is, for example, an electrical insulating member made of synthetic resin. The insulator 5 may be molded by any molding method, for example, injection molding.

[0016] The insulator 5 has a main body portion that covers the outer peripheral surfaces of the multiple teeth 42 and the inner peripheral surface of the yoke 41, as well as a winding holding portion 51. The winding holding portion 51 may be disposed at either one end in the axial direction of the stator core 4. In the illustrated example, the winding holding portion 51 is disposed at the upper end side of the stator core 4, but it may also be disposed at the lower end side of the stator core 4, for example. The winding holding portion 51 is formed in an annular shape centered on the axis O.

[0017] The winding holding portion 51 is formed with a plurality of transition grooves 52 that are recessed from the outer periphery and extend circumferentially. The transition grooves 52 are aligned in the axial direction. Each transition groove 52 accommodates a transition wire portion 62 of the winding 6, which will be described later. The transition grooves 52 accommodate the transition wire portions 62 of the windings 6 of different phases. In this embodiment, there are three transition grooves 52. The three transition wire portions 62 accommodate the transition wire portions 62 of the windings 6 of three phases (U phase, V phase, and W phase). In the illustrated example, the transition groove 52U for the U phase, the transition groove 52V for the V phase, and the transition groove 52W for the W phase are aligned in this order upward in the axial direction.

[0018] The insulator 5 illustrated in Fig. 2 is divided in both the axial and circumferential directions. The insulator 5 includes an upper-end insulator 55, an intermediate insulator 56, and a lower-end insulator 57, which are arranged in this order from top to bottom in the axial direction. The upper-end insulator 55 is attached to the upper end of the stator core 4 in the axial direction. The upper-end insulator 55 includes the winding holding portion 51 described above. The intermediate insulator 56 is attached to a middle portion of the stator core 4 in the axial direction. The lower-end insulator 57 is attached to the lower end of the stator core 4 in the axial direction. The upper-end insulator 55 is connected to the upper end of the intermediate insulator 56. The lower-end insulator 57 is connected to the lower end of the intermediate insulator 56.

[0019] <Windings> As shown in FIGS. 1 and 5 , the multiple windings 6 are wound around the multiple teeth 42 via the insulators 5. In FIG. 5 , the stator 3 is linearly expanded so that the circumferential direction of the stator 3 extends in the left-right direction, and only the teeth 42 of the stator 3, the three crossover grooves 52 of the insulator 5, and the three windings 6 are schematically shown, with the main body of the insulator 5 and other components omitted. An example of a wiring diagram for the windings 6 is also shown, divided into three phases: U-phase, V-phase, and W-phase. As shown in FIG. 5 , each of the multiple windings 6 has multiple coil portions 61, at least one crossover portion 62, and two lead-out portions 63. In the same winding 6, the multiple coil portions 61 are wound around each tooth 42 by concentrated winding. In FIG. 5 , the coil portion 61 is depicted surrounding the tooth 42 from below, but in reality, the coil portion 61 is wound around the tooth 42 by concentrated winding.

[0020] The crossover portion 62 connects adjacent coil portions 61. The number of crossover portions 62 is one less than the number of coil portions 61. The two lead-out portions 63 form the ends of the same winding 6 and extend from the coil portion 61. In this embodiment, the winding 6 is a multi-filament wire formed by bundling multiple strands of wire in a non-aligned manner. Note that the winding 6 may also be, for example, a single strand of wire.

[0021] In this embodiment, there are three windings 6, and each of the three windings 6 is assigned to one of three phases (U-phase, V-phase, and W-phase). That is, the three windings 6 include a U-phase winding 6U, a V-phase winding 6V, and a W-phase winding 6W. The three phase windings 6U, 6V, and 6W have the same number of coil portions 61. In this embodiment, the number of parallel connections of the windings 6U, 6V, and 6W of each phase is one. However, the number of parallel connections of the windings 6U, 6V, and 6W of each phase may be, for example, two or more.

[0022] As shown in Figure 4, the three windings 6 form a three-phase AC circuit. The three-phase AC circuit employs a star connection in which the three phase windings 6 are connected at a neutral point N1. If two or more windings 6 are connected in parallel for each phase, the same number of star connections as shown in Figure 4 should be prepared, and the input points U1, V1, and W1 of the same phase in the multiple star connections should be connected to the same connection terminal. The input points U1, V1, and W1 are first ends of the windings 6 in the longitudinal direction and are terminals for inputting drive current to the windings 6.

[0023] In the motor 1 of this embodiment, the number of poles of the rotor 2 and the number of slots 43 of the stator core 4 are set to satisfy either the following conditional formula (1) or (2): (Conditional formula (1)) P:S=2n:3n (Conditional formula (2)) P:S=4n:3n In conditional formulas (1) and (2), P is the number of poles of the rotor 2 (the number of magnetic poles formed by the magnets 23), S is the number of slots 43 of the stator core 4, and n is a natural number equal to or greater than 2. The number of slots S corresponds to the total number of coil portions 61. That is, the total number of coil portions 61 is set to 3n. In the motor 1 that satisfies conditional formulas (1) and (2), the coil portions 61 are all wound around the teeth 42 in the same direction. In FIG. 5 , all of the coil portions 61 are wound counterclockwise around the teeth 42. In the motor 1 illustrated in Figure 3, one magnet 23 forms one magnetic pole, so the number of magnets 23 (number of poles P) is four and the number of slots 43 (number of slots S) is six, satisfying conditional formula (1).

[0024] For example, when the natural number n is 12, the number of slots 43 (number of slots S) is 36. In the stator 3 illustrated in FIG. 2, the number of slots 43 is 36. In the stator 3 illustrated in FIG. 2, the total number of coil portions 61 is 36. Furthermore, when the natural number n is 2, the number of slots 43 (number of slots S) is 6. In the stator 3 illustrated in FIG. 3, the number of slots 43 is 6. In the stators 3 illustrated in FIGS. 3 and 5, the total number of coil portions 61 is 6.

[0025] As shown in FIG. 5 , in the stator 3, the coil portions 61 of the U-phase winding 6U (U-phase coil portion 61U), the coil portions 61 of the V-phase winding 6V (V-phase coil portion 61V), and the coil portions 61 of the W-phase winding 6W (W-phase coil portion 61W) are arranged in a circumferentially repeated order. Therefore, the coil portions 61 of the windings 6 of the same phase are wound around every third tooth 42. For example, if the number of slots S is six, the two coil portions 61 of the U-phase winding 6U are wound around the first and fourth teeth 42 (42-1, 42-4). The two coil portions 61 of the V-phase winding 6V are wound around the second and fifth teeth 42 (42-2, 42-5). The two coil portions 61 of the W-phase winding 6W are wound around the third and sixth teeth 42 (42-3, 42-6). 5 shows a stator 3 that satisfies conditional formula (1), in which the U-phase coil portion 61U, the V-phase coil portion 61V, and the W-phase coil portion 61W are arranged in sequence in a repeated manner toward the right. Therefore, the numbers of the teeth 42 described above are arranged in sequence from the left end toward the right. In addition, in a stator 3 that satisfies conditional formula (2), the U-phase coil portion 61U, the W-phase coil portion 61W, and the V-phase coil portion 61V are arranged in sequence in a repeated manner toward the right in FIG. 5.

[0026] In the stator 3 illustrated in FIG. 5 , the second ends of the windings 6, located opposite the first ends forming the input points U1, V1, and W1, are output points Un1, Vn1, and Wn1. The three-phase output points Un1, Vn1, and Wn1 form the neutral point N1 of the star connection shown in FIG. 4 . Specifically, the three-phase output points Un1, Vn1, and Wn1 are connected to each other by a neutral conductor NL1, thereby forming the neutral point N1. The three-phase output points Un1, Vn1, and Wn1 are located at positions drawn from three circumferentially adjacent coil portions 61 (61U-2, 61V-2, and 61W-2). This allows the three-phase output points Un1, Vn1, and Wn1 to be located close to each other, thereby shortening the neutral conductor NL1 connecting the three-phase output points Un1, Vn1, and Wn1.

[0027] In the stator 3 illustrated in Fig. 5, each winding 6 has two coil portions 61. Therefore, each winding 6 has only one crossover portion 62. As a result, in a coil portion 61 from which a lead portion 63 is drawn out from one circumferential side, a crossover portion 62 is drawn out from the other circumferential side. The crossover portion 62 drawn out from the other circumferential side of a given coil portion 61 extends from the given coil portion 61 to the other circumferential side in the crossover groove 52.

[0028] 5, for example, a lead wire portion 63 is drawn out from the left side of a first coil portion 61-1 (61U-1, 61V-1, 61W-1) located on the left side of the same winding 6. A crossover portion 62 is drawn out from the right side of the first coil portion 61-1, and extends to the right. Meanwhile, a lead wire portion 63 is drawn out from the right side of a second coil portion 61-2 (61U-2, 61V-2, 61W-2) located on the right side. A crossover portion 62 is drawn out from the left side of the second coil portion 61-2, and extends to the left.

[0029] <Method of Manufacturing the Motor> When manufacturing the motor of this embodiment, for example, the multiple windings 6 can be formed by the following procedure. For example, when forming the U-phase winding 6U, first, a first step is performed in which the first coil portion 61U-1 is formed by concentrating winding from one circumferential side of the first tooth 42-1 around the first tooth 42-1 while forming the first lead-out portion 63. Next, a second step is performed in which the wire is drawn to the other circumferential side of the first tooth 42-1 and extended to the other circumferential side of the first tooth 42-1 while being accommodated in the jumper groove 52U, thereby forming the jumper portion 62. After that, a third step is performed in which the second coil portion 61U-2 is formed by concentrating winding from one circumferential side of the second tooth 42-4, which is located on the other circumferential side of the first tooth 42-1, around the second tooth 42-4. Finally, a fourth step is performed in which the second lead-out portion 63 is formed by drawing the wire to the other circumferential side of the second tooth 42-4, thereby forming the U-phase winding 6U. The V-phase winding 6V and the W-phase winding 6W can be formed in the same manner as the method for forming the U-phase winding 6U described above.

[0030] <Effects> As described above, in the stator 3 of this embodiment, the lead wire portions 63 are led out from one circumferential side of a given coil portion 61. Furthermore, in a given coil portion 61, the crossover wire portions 62 are led out from the other circumferential side and extend to the other circumferential side of the coil portion 61. Therefore, the crossover wire portions 62 extending from the coil portion 61 do not extend across the coil portion 61 from the other circumferential side to one side in the crossover groove 52. Furthermore, the lead wire portions 63 extending from the coil portion 61 do not extend across the coil portion 61 from one circumferential side to the other side in the crossover groove 52. This prevents the crossover wire portions 62 and the lead wire portions 63 constituting the same winding 6 from crossing each other. That is, the same winding 6 can be prevented from crossing each other in the crossover groove 52 and in the vicinity of the crossover groove 52.

[0031] The same winding 6 does not cross over in the jumper grooves 52 and in the vicinity of the jumper grooves 52, thereby preventing the winding 6 from collapsing. Even if a multi-strand wire, which is prone to collapsing, is used as the winding 6, the winding 6 can be prevented from collapsing. This ensures a sufficient creepage distance between the jumper wire portions 62 housed in different jumper grooves 52. Furthermore, since the occurrence of defective products for which the creepage distance cannot be ensured can be prevented, a decrease in yield can also be prevented.

[0032] Furthermore, in the stator 3 of this embodiment, the same windings 6 do not cross over each other in the jumper grooves 52 and in the vicinity of the jumper grooves 52, which allows the overall length of the windings 6 to be kept short compared to when such crossings are present. Also, by keeping the overall length of the windings 6 short, the resistance value of the windings 6 can be reduced. This improves the efficiency of the motor including the stator 3. Furthermore, because the same windings 6 do not cross over each other in the jumper grooves 52 and in the vicinity of the jumper grooves 52, this prevents the windings 6 from rubbing against each other at these crossings, which would otherwise scrape off the insulating coating of the windings 6 and form pinholes in the insulating coating. Therefore, the insulation of the windings 6 can be ensured.

[0033] Other Embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to these and can be modified as appropriate within the scope of the technical idea of ​​the invention.

[0034] In the present disclosure, as illustrated in Fig. 6, the same winding 6 may have three or more coil portions 61. In Fig. 6 as well, the coil portions 61 are depicted as surrounding the teeth 42 from below, but in reality, they are wound around the teeth 42 using concentrated winding. When the same winding 6 has three or more coil portions 61, the multiple coil portions 61 include two end coil portions 61-4 located at both ends of the arrangement direction of the multiple coil portions 61 (the left-right direction in Fig. 6), and a middle coil portion 61-5 located between the two end coil portions 61-4.

[0035] The end coil portion 61-4 has a lead wire portion 63 drawn from one circumferential side thereof and a crossover wire portion 62 drawn from the other circumferential side thereof. The crossover wire portion 62 drawn from the other circumferential side of the end coil portion 61-4 extends to the other circumferential side of the end coil portion 61-4. For example, in FIG. 6 , the lead wire portion 63 is drawn from the left side of the end coil portion 61-4 located at the left end. The crossover wire portion 62 is drawn from the right side of the end coil portion 61-4 located at the left end, and extends to the right. Meanwhile, the lead wire portion 63 is drawn from the right side of the end coil portion 61-4 located at the right end. The crossover wire portion 62 is drawn from the left side of the end coil portion 61-4 located at the right end, and extends to the left. This makes it possible to prevent the crossover wire portion 62 and the lead wire portion 63 that constitute the same winding 6 from crossing each other in the crossover groove 52 and in the vicinity of the crossover groove 52 .

[0036] The crossover wire portion 62 drawn out from the intermediate coil portion 61-5 to one circumferential side extends to one circumferential side of the intermediate coil portion 61-5. Similarly, the crossover wire portion 62 drawn out from the intermediate coil portion 61-5 to the other circumferential side extends to the other circumferential side of the intermediate coil portion 61-5. For example, the crossover wire portion 62 drawn out to the right side of the intermediate coil portion 61-5 shown in FIG. 6 extends to the right from the intermediate coil portion 61-5. Similarly, the crossover wire portion 62 drawn out to the left side of the intermediate coil portion 61-5 extends to the left from the intermediate coil portion 61-5. This prevents the crossover wire portions 62 constituting the same winding 6 from crossing each other at the crossover groove 52.

[0037] The above-described arrangement of the crossover wires 62 and the lead-out wires 63 drawn from the end coil portion 61-4 and the intermediate coil portion 61-5 provides the same effect as in the above-described embodiment, i.e., it is possible to prevent the same winding 6 from crossing over in the crossover grooves 52 and in the vicinity of the crossover grooves 52.

[0038] 6 shows only the U-phase winding 6U, but the V-phase and W-phase windings 6 are configured in the same manner. The stator shown in FIG. 6 has three coil portions 61 in each phase winding 6, for a total of nine windings 6 for the three phases. In other words, the stator shown in FIG. 6 is applicable to a motor that satisfies conditional expressions (1) and (2).

[0039] As shown in FIG. 6 , when a single winding 6 has three or more coil portions 61, the motor manufacturing method can form each of the windings 6, for example, by the following procedure. For example, when forming the U-phase winding 6U shown in FIG. 6 , a first step is performed in which a first end coil portion 61-4 is formed by concentrating winding around the first teeth 42 from one circumferential side of the first teeth 42 while forming a first lead-out portion 63. Next, a second step is performed in which the first end coil portion 61-4 is drawn out to the other circumferential side of the first teeth 42 and extended to the other circumferential side of the first teeth 42 while being accommodated in the jumper groove 52U, thereby forming a jumper portion 62. After that, a fifth step is performed in which an intermediate coil portion 61-5 is formed by concentrating winding around the third teeth 42 from one circumferential side of the third teeth 42, which are spaced apart from the first teeth 42 in the other circumferential direction. Furthermore, after the fifth step, a sixth step is carried out in which another crossover wire portion 62 is formed by pulling it out to the other circumferential side of the third tooth 42 and extending it to the other circumferential side of the third tooth 42 while accommodating it in the crossover groove 52U.

[0040] Then, after the sixth step, a third step is carried out in which the second end coil portion 61-4 is formed by concentrated winding from one circumferential side of the second tooth 42, which is located on the other circumferential side of the third tooth 42. Finally, a fourth step is carried out in which the second lead-out portion 63 is formed by leading out to the other circumferential side of the second tooth 42, thereby forming the winding 6U illustrated in FIG. 6. Note that if the same winding 6 has multiple intermediate coil portions 61-5, the fifth and sixth steps may be repeated multiple times. The V-phase winding 6V and the W-phase winding 6W, each having an intermediate coil portion 61-5, can be formed using the same procedure as the method for forming the U-phase winding 6U described above.

[0041] According to one aspect of the present disclosure, it is possible to prevent the windings in a motor from becoming unwound.

[0042] 1...motor, 2...rotor, 3...stator, 4...stator core, 5...insulator, 6...winding, 42...teeth, 43...slot, 51...winding holding portion, 52...crossover groove, 61...coil portion, 61-4...end coil portion, 61-5...intermediate coil portion, 62...crossover portion, 63...drawing wire portion, P...number of poles, S...number of slots

Claims

1. A stator comprising: a rotor; an annular stator core having a plurality of teeth and a plurality of slots arranged in the circumferential direction; an insulator attached to the stator core; and a plurality of windings wound around the plurality of teeth via the insulator, wherein the condition P:S=2n:3n or P:S=4n:3n is satisfied, where P is the number of poles of the rotor, S is the number of slots in the stator core, and n is a natural number equal to or greater than 2, and the insulator has a winding holding portion located at either end in the axial direction of the stator core, the winding holding portion having a plurality of jumper grooves recessed from the outer periphery and extending in the circumferential direction and arranged in the axial direction, and each of the plurality of windings has a plurality of coil portions wound around the teeth by concentrated winding, lead-out portions constituting the ends of the windings and extending from the coil portions, and jumper portions in which different phases are accommodated in the plurality of jumper grooves and connecting adjacent coil portions, The coil section has the lead wire section drawn out from one side in the circumferential direction, and the jumper wire section drawn out from the other side in the circumferential direction, and the jumper wire section drawn out from the other side in the circumferential direction of the coil section extends to the other side in the circumferential direction relative to the coil section.

2. The motor according to claim 1, wherein the same winding has three or more of the coil sections, and the multiple coil sections constituting the same winding include two end coil sections located at both ends in the arrangement direction of the multiple coil sections, and an intermediate coil section located between the two end coil sections, and the end coil section from which the lead wire section is drawn out from one side in the circumferential direction has the jumper wire section drawn out from the other side in the circumferential direction, and the jumper wire section drawn out from the other side in the circumferential direction of the end coil section extends to the other side in the circumferential direction relative to the end coil section, the jumper wire section drawn out from one side in the circumferential direction of the intermediate coil section extends to one side in the circumferential direction relative to the intermediate coil section, and the jumper wire section drawn out from the other side in the circumferential direction of the intermediate coil section extends to the other side in the circumferential direction relative to the intermediate coil section.

3. A motor according to claim 1 or claim 2, wherein the winding is a multi-filament winding in which a plurality of strands are bundled together in a non-aligned manner.

4. A method for manufacturing a motor as defined in claim 1 or 2, wherein each of the plurality of windings is formed by carrying out the following steps: a first step of forming a first coil portion by concentrating winding from one circumferential side of a first tooth around the first tooth while forming a first pull-out portion; a second step of forming the jumper portion after the first step by pulling out the winding to the other circumferential side of the first tooth and extending it to the other circumferential side of the first tooth while being accommodated in the jumper groove; a third step of forming a second coil portion after the second step by concentrating winding from one circumferential side of a second tooth located away from the first tooth on the other circumferential side of the first tooth around the second tooth; and a fourth step of forming a second pull-out portion after the third step by pulling out the winding to the other circumferential side of the second tooth.

5. A method for manufacturing a motor as described in claim 4, wherein each of the plurality of windings further includes a fifth step, after the second step, of concentrating winding the windings from one circumferential side of a third tooth located away from the first tooth on the other circumferential side thereof around the third tooth to form an intermediate coil portion, and a sixth step, after the fifth step, of drawing the windings out to the other circumferential side of the third tooth and extending them to the other circumferential side of the third tooth while being housed in the jumper groove to form the jumper wire portion, and wherein in the third step, after the sixth step, the second coil portion is formed by concentrating winding the windings from one circumferential side of the second tooth located away from the third tooth on the other circumferential side thereof around the second tooth.

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